The present invention relates to a part mounting system for mounting electronic parts on a substrate and a part mounting method. More particularly, the present invention relates to a part mounting system that mounts electronic parts on a substrate by pressing the same through connecting members against the substrate, and a part mounting method.
A known part mounting system for use in fabricating a flat panel display, such as a liquid crystal display, bonds electronic parts, such as flexible printed circuits (abbreviated to xe2x80x9cFPCsxe2x80x9d), to a substrate, such as a glass substrate, by pressing the electronic parts through connecting members, such as anisotropic conductive films (abbreviated to xe2x80x9cACFsxe2x80x9d), against the substrate.
There is a growing tendency for the size of panels of flat panel displays fabricated by using such a part mounting system to increase. Generally, a plurality of FPCs are attached by bonding to both first and second surfaces of a glass substrate. A conventional part mounting system has an upper bonding unit that presses an FPC against a glass substrate from above the glass substrate and a lower bonding unit that presses an FPC against the same glass substrate from below the glass substrate. The upper and the lower bonding unit are disposed at different positions, respectively, beside a glass substrate carrying path. The glass substrate is aligned with the upper bonding unit when attaching an FPC to the first surface of the glass substrate or with the lower bonding unit when attaching an FPC to the second surface of the glass substrate, and then the FPC is pressed against and attached to the glass substrate one at a time.
This conventional part mounting system attaches FPCs to the first and the second surface of the glass substrate by bonding by using the upper and the lower bonding unit disposed respectively at the different positions. Therefore, the conventional part mounting system needs a large floor space for installation.
The present invention has been made in view of this problem and it is therefore an object of the present invention to provide a part mounting system that needs a relatively small floor space for installation, and a part mounting method.
According to a first aspect of the present invention, a part mounting system comprises: an electronic part carrying apparatus that carries an electronic part; a substrate feed apparatus that feeds a substrate; an aligning apparatus that aligns an electronic part carried by the electronic part carrying apparatus and a substrate fed by the substrate feed apparatus; and a bonding apparatus that bonds the electronic part aligned with the substrate to the substrate by pressing; wherein the bonding apparatus includes a first pressing unit that presses the electronic part against an upper surface of the substrate from above the substrate, and a second pressing unit that presses the electronic part against a lower surface of the substrate from below the substrate, each of the first and the second pressing unit has a tool that is applied to the substrate and the electronic part, and a pressure applying device that selectively applies a bonding pressure or a backup pressure to the tool.
In the part mounting system in the first aspect of the present invention, it is preferable that the pressure applying device includes a pair of lifting devices that apply the bonding pressure or the backup pressure to the tool, and a pressure adjusting device that adjusts a pressure to be exerted by the lifting devices on the tool.
According to a second aspect of the present invention, a part mounting method comprises the steps of: feeding an electronic part; feeding a substrate; aligning the fed electronic part and the fed substrate; and bonding the electronic part aligned with the substrate through a connecting member to the substrate; wherein the step of bonding the electronic part to the substrate includes the steps of: selecting either a first pressing unit that presses the electronic part against an upper surface of the substrate from above the substrate or a second pressing unit that presses the electronic part against a lower surface of the substrate from below the substrate to bond the electronic part to the substrate on the basis of electronic part mounting information stored in a storage device; and applying a bonding pressure to a tool included in the pressing unit selected for bonding the electronic part to the substrate and applying a backup pressure to a tool included in the other bonding unit.
The part mounting system according to the present invention is provided with the bonding apparatus including the pair of pressing units that press electronic parts against the upper and the lower surface of a substrate, and either the bonding pressure or the backup pressure can be selectively applied to each of the pressing units. Therefore, only the pair of bonding units is necessary for attaching electronic parts by bonding to both the surfaces of the substrate and hence the part mounting system needs a relatively small floor space for installation. Since the pressure applying device has the pair of lifting devices for applying the bonding pressure or the backup pressure to the tool, and the pressure adjusting device for adjusting a pressure to be exerted by the lifting devices, an optimum pressure can be used for bonding according to the type of electronic parts or the number of electronic parts to be simultaneously bonded to the substrate.